Tandem solar cells and photovoltaic modules

Abstract

This application relates to the field of solar cell technology, particularly to stacked solar cells and photovoltaic modules. In an embodiment of the application, the area of ​​the orthographic projection of a first passivation contact layer on a reference surface is configured to be smaller than the area of ​​the overlapping projections of the top and bottom battery cells. The first passivation layer is disposed on a first sub-surface exposed through the first passivation contact layer and a first target surface of the first passivation contact layer, so that the composite layer and the first passivation layer's facing surfaces contact each other, thereby improving the efficiency of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to stacked solar cells and photovoltaic modules. Background Art

[0002] Perovskite and perovskite-silicon tandem solar cells have become a hot topic in the field of solar cell technology due to their excellent photoelectric conversion efficiency. Therefore, how to further improve the photoelectric conversion efficiency of cells has become the key to the development of this field. Summary of the Invention

[0003] Based on this, it is necessary to provide a stacked solar cell and a photovoltaic module to improve the efficiency of the cell.

[0004] According to one aspect of the present application, an embodiment of the present application provides a tandem solar cell comprising a top cell and a bottom cell stacked along a first direction, and a recombination layer located between the top cell and the bottom cell. The orthographic projections of the top cell and the bottom cell on a reference plane are overlapping, and the reference plane is a plane perpendicular to the first direction. The bottom cell comprises a substrate and a first passivation contact layer, the first passivation contact layer comprising a first tunneling layer and a first doped conductive layer stacked on a surface of the substrate facing the top cell. The orthographic projection of the first passivation contact layer on the reference plane is within the overlapping projection range, and the area of ​​the orthographic projection of the first passivation contact layer on the reference plane is smaller than the area of ​​the overlapping projection. A portion of the substrate surface facing the top cell that is exposed through the first passivation contact layer is a first sub-surface. The first passivation contact layer has a first target surface that is not in contact with the substrate surface facing the top cell and is located within the tandem solar cell. The tandem solar cell further comprises a first passivation layer disposed on the first sub-surface and the first target surface. The recombination layer and the first passivation layer are in contact with each other on their facing surfaces.

[0005] In some embodiments, the first passivation contact layer includes a plurality of first passivation contact portions disposed at intervals.

[0006] In some embodiments, at least some of the first passivation contact portions are spaced apart along the third direction, and the first passivation contact portions are longitudinally extended along the second direction. The second direction and the third direction intersect with each other and are both perpendicular to the first direction.

[0007] In some embodiments, the first passivation contact layer is provided with a plurality of first through holes penetrating the first passivation contact layer along a first direction.

[0008] In some embodiments, the first passivation contact layer includes a plurality of first sub-sections and a plurality of second sub-sections. The first sub-sections extend along the fourth direction and are spaced apart along the fifth direction. The second sub-sections are spaced apart along the fourth direction. Each second sub-section is connected to any one of all the first sub-sections. The fourth direction and the fifth direction intersect each other and are both perpendicular to the first direction.

[0009] In some embodiments, the material of the first passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

[0010] In some embodiments, the material of the first passivation layer includes metal oxide, and the thickness of the first passivation layer is 1nm to 50nm; or, the material of the first passivation layer includes non-metal nitride or non-metal nitride oxide, and the thickness of the first passivation layer is 50nm to 100nm.

[0011] In some embodiments, the composite layer includes a first portion and a second portion. An orthographic projection of the first portion on a reference surface overlaps an orthographic projection of the first passivation contact layer on the reference surface. A portion of the second portion not in contact with the first passivation contact layer has a thickness less than a thickness of the first portion.

[0012] In some embodiments, the tandem solar cell further includes a second passivation layer, and the second passivation layer is disposed on a surface of the composite layer facing away from the bottom battery unit.

[0013] In some embodiments, the second passivation layer is configured as a monolayer.

[0014] In some embodiments, the second passivation layer has a thickness of 0.3 nm to 2 nm.

[0015] In some embodiments, the bottom battery cell further includes a second passivation contact layer, comprising a second tunneling layer and a second doped conductive layer stacked on a surface of the substrate facing away from the top battery cell. The orthographic projection of the second passivation contact layer on the reference plane is within the overlapping projection range, and the area of ​​the orthographic projection of the second passivation contact layer on the reference plane is smaller than the area of ​​the overlapping projection.

[0016] In some embodiments, the second passivation contact layer includes a plurality of second passivation contacts disposed at intervals.

[0017] In some embodiments, the second passivation contact layer is provided with a plurality of second through holes penetrating the second passivation contact layer along the first direction.

[0018] In some embodiments, the portion of the substrate surface facing away from the top cell that is exposed through the second passivation contact layer is a second sub-surface. The second passivation contact layer has a second target surface that is not in contact with the substrate surface facing away from the top cell and is located within the tandem solar cell. The tandem solar cell further includes a third passivation layer disposed on the second sub-surface and the second target surface.

[0019] In some embodiments, the material of the third passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

[0020] In some embodiments, the material of the third passivation layer includes metal oxide, and the thickness of the third passivation layer is 1nm to 50nm; or, the material of the third passivation layer includes non-metal nitride or non-metal nitride oxide, and the thickness of the third passivation layer is 50nm to 100nm.

[0021] In some embodiments, the bottom battery cell further comprises a doping layer disposed on a surface of the substrate facing away from the top battery cell. The orthographic projection of the doping layer on the reference plane is within the overlapping projection range, and the area of ​​the orthographic projection of the doping layer on the reference plane is smaller than the area of ​​the overlapping projection.

[0022] In some embodiments, the doping layer includes a plurality of spaced-apart doping portions.

[0023] In some embodiments, the doping layer is provided with a plurality of third through holes penetrating the doping layer along the first direction.

[0024] In some embodiments, the portion of the substrate side facing away from the top cell that is exposed through the doped layer is a third sub-surface. The doped layer has a third target surface that is not in contact with the substrate side facing away from the top cell and is located within the tandem solar cell. The tandem solar cell further includes a fourth passivation layer disposed on the third sub-surface and the third target surface.

[0025] In some embodiments, the material of the fourth passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

[0026] In some embodiments, the material of the fourth passivation layer includes metal oxide, and the thickness of the fourth passivation layer is 1nm to 50nm; or, the material of the fourth passivation layer includes non-metal nitride or non-metal nitride oxide, and the thickness of the fourth passivation layer is 50nm to 100nm.

[0027] In some embodiments, the top cell includes a first charge transport layer, a light absorbing layer, a second charge transport layer, and a transparent electrode layer stacked and arranged away from the bottom cell. The transparent electrode layer includes a first sublayer and a second sublayer, the first sublayer being disposed on a surface of the second charge transport layer facing away from the light absorbing layer, and the second sublayer being disposed on a surface of the first sublayer facing away from the second charge transport layer. The orthographic projection and the overlapping projection of the first sublayer on the reference surface overlap. The orthographic projection of the second sublayer on the reference surface is within the overlapping projection range, and the area of ​​the orthographic projection of the second sublayer on the reference surface is smaller than the area of ​​the overlapping projection.

[0028] According to another aspect of the present application, an embodiment of the present application provides a photovoltaic module comprising a cell string, an encapsulation layer, and a cover plate. The encapsulation layer is used to cover the surface of the cell string. The cover plate is used to cover the surface of the encapsulation layer away from the cell string. The cell string is formed by connecting multiple stacked solar cells as described in any of the above embodiments.

[0029] In the aforementioned tandem solar cell and photovoltaic module, the bottom cell of the tandem solar cell includes a substrate and a first passivation contact layer, and the first passivation contact layer includes a first tunneling layer and a first doped conductive layer. By configuring the area of ​​the orthographic projection of the first passivation contact layer on a reference plane to be smaller than the area of ​​the overlapping projections of the top and bottom cell, the first passivation contact layer covers a portion of the substrate surface facing the top cell. This not only reduces optical parasitic absorption of the first doped conductive layer, improving the cell's optical loss and thereby increasing the cell's short-circuit current, but also increases the physical contact area and electrical connection efficiency of the interface, reducing the resistance between the interfaces, thereby facilitating the conduction and collection of minority carriers by the cell and thereby improving the cell's fill factor. At the same time, because the first passivation layer is provided on the first sub-surface exposed by the first passivation contact layer and the first target surface of the first passivation contact layer, the surfaces of the composite layer and the first passivation layer facing each other are in contact with each other. This not only reduces film defects in the first passivation contact layer, reduces recombination centers, and improves the consistency and reliability of the first passivation contact layer, but also reduces the potential energy barrier between film layers, thereby facilitating the conduction and collection of minority carriers in the battery, thereby improving the open circuit voltage and fill factor of the battery. Therefore, the interaction between the first passivation contact layer and the first passivation layer can improve the efficiency of the battery.

[0030] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0032] Figure 1 is a schematic cross-sectional view of a stacked solar cell in some embodiments of the present application;

[0033] Figure 2 Schematic diagram of a cross-sectional structure of a substrate, a first passivation contact layer, a first passivation layer, and a composite layer in some embodiments of the present application;

[0034] Figure 3 Schematic diagram of the relationship between the first projection and the second projection in some embodiments of the present application;

[0035] Figure 4 Schematic diagram of a top view of the structure of the substrate and the first passivation contact layer in cooperation with each other in some other embodiments of the present application;

[0036] Figure 5 Schematic diagram of a top view of the substrate and the first passivation contact layer in cooperation with each other in some other embodiments of the present application;

[0037] Figure 6 Schematic diagram of a top view of the structure of the substrate and the first passivation contact layer in some other embodiments of the present application;

[0038] Figure 7 Schematic diagrams of cross-sectional structures of stacked solar cells in other embodiments of the present application;

[0039] Figure 8 for Figure 7 A schematic diagram of a cross-sectional structure of a composite layer in a tandem solar cell is shown in FIG.

[0040] Figure 9 Schematic diagram of the cross-sectional structure of a stacked solar cell in some further embodiments of the present application;

[0041] Figure 10 for Figure 9 A schematic cross-sectional view of the structure of the composite layer and the second passivation layer in the stacked solar cell shown in FIG.

[0042] Figure 11 Schematic diagram of the cross-sectional structure of a stacked solar cell in some other embodiments of the present application;

[0043] Figure 12 for Figure 11 A schematic cross-sectional view of a partial structure of a stacked solar cell shown in FIG.

[0044] Figure 13 A schematic top view of the structure of the substrate and the second passivation contact structure in some other embodiments of the present application;

[0045] Figure 14 Schematic diagram of the cross-sectional structure of a stacked solar cell in some other embodiments of the present application;

[0046] Figure 15 for Figure 14 A schematic cross-sectional view of a partial structure of a stacked solar cell shown in FIG.

[0047] Figure 16 Schematic diagram of a top view of the structure of the substrate and the doping layer in some other embodiments of the present application;

[0048] Figure 17 Schematic diagram of the cross-sectional structure of a stacked solar cell in some further embodiments of the present application;

[0049] Figure 18 Schematic diagram of the cross-sectional structure of a stacked solar cell in some other embodiments of the present application;

[0050] Figure 19 Schematic diagram of the cross-sectional structure of a stacked solar cell in some other embodiments of the present application;

[0051] Figure 20 Schematic diagram of the structure of photovoltaic modules in some embodiments of the present application.

[0052] Description of reference numerals:

[0053] Tandem solar cells 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100i;

[0054] Top battery cells 110a, 110b, first charge transport layer 111, light absorption layer 112, second charge transport layer 113, transparent electrode layers 114a, 114b, first sublayer 1141, second sublayer 1142, protective layer 115;

[0055] bottom battery cells 120a, 120b, 120c;

[0056] substrate 121, first surface m1, first sub-surface m11, second surface m2, second sub-surface m21, third sub-surface m22;

[0057] first passivation contact layers 122a, 122b, 122c, 122d, first tunneling layer 1221a, first doped conductive layer 1222a, first target surface t1, first passivation contact portions 1220a, 1220b, first through hole k1, first sub-portion 12201, second sub-portion 12202;

[0058] second passivation contact layers 123a, 123b, 123c, second tunneling layers 1231a, 1231b, second doped conductive layers 1232a, 1232b, second target surface t2, second passivation contact portion 1230, second through hole k2;

[0059] doped layers 124a, 124b, doped portion 1240, third through hole k3, third target surface t3;

[0060] Composite layers 130a, 130b, first portion 131, first thickness d1, second portion 132, second thickness d2, target portion 1321;

[0061] A first passivation layer 140 having a first size h1;

[0062] The second passivation layer 150 has a second size h2;

[0063] The third passivation layer 160a, 160b has a third size h3;

[0064] Fourth passivation layer 170 , fourth size h4;

[0065] a first electrode 180;

[0066] a second electrode 190;

[0067] First projection y1, second projection y2, reference surface E;

[0068] First direction F1, second direction F2, third direction F3, fourth direction F4, fifth direction F5;

[0069] Photovoltaic module 10, cell string 11, encapsulation layer 12, cover plate 13, conductive tape 14. DETAILED DESCRIPTION

[0070] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0071] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0072] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0073] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. It is worth noting that in the following description and the attached claims, "electrical connection" between one feature and another feature not only includes one feature being in direct contact with another feature to form an electric energy transmission or current transmission channel, but also includes an intermediate feature between one feature and another feature, and the one feature, the other feature and the intermediate feature between them form an electric energy transmission channel or a current transmission channel to achieve electric energy transmission or transmission. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0074] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0075] It should be noted that if an element or layer is referred to as being "on," "adjacent to," "connected to," "coupled to," "fixed to," or "disposed on" another element or layer, it may be directly on the other element or layer or there may also be an intervening element or layer. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be an intervening element. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or portions, these elements, components, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Thus, without departing from the teachings of the present application, a first element, component, region, layer, doping type, or portion discussed below could be referred to as a second element, component, region, layer, or portion; for example, a first doping type could be referred to as a second doping type, and similarly, a second doping type could be referred to as a first doping type; or the first doping type and the second doping type could be different doping types, for example, the first doping type could be P-type and the second could be N-type, or the first doping type could be N-type and the second could be P-type. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions, if used herein, are for illustrative purposes only and are not intended to be limiting. It should be understood that spatially relative terms encompass different orientations of the device in use and operation, in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, an element or feature described as "below," "beneath," or "beneath" another element or feature would then be oriented "above" the other element or feature. Thus, the exemplary terms "below" and "below" could encompass both an above and a below orientation. Furthermore, the device may be incorporated at alternative orientations (eg, rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

[0076] Moreover, while the embodiments of the present invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the present invention, variations from the illustrated shapes as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, the embodiments of the present invention should not be limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing techniques.

[0077] According to some embodiments of this application, please refer to Figure 1 , Figure 1 Figure 1 is a schematic cross-sectional view of a tandem solar cell 100a in some embodiments of the present application. Embodiments of the present application provide a tandem solar cell 100a comprising a top cell 110a and a bottom cell 120a stacked along a first direction F1, and a composite layer 130a positioned between the top cell 110a and the bottom cell 120a. The bottom cell 120a comprises a substrate 121 and a first passivation contact layer 122a. The first passivation contact layer 122a comprises a first tunneling layer 1221a and a first doped conductive layer 1222a stacked on a surface of the substrate 121 facing the top cell 110a.

[0078] The first direction F1 is the thickness direction of the tandem solar cell 100a. For example, the bottom cell 120a may be a TOPCon (Tunnel Oxide Passivating Contacts) cell, and the top cell 110a may be a perovskite cell. The bottom cell 120a may be a single-sided TOPCon cell or a double-sided TOPCon cell, without specific limitation. In other words, depositing the wide-bandgap top cell 110a on the bottom cell 120a creates a tandem cell, maximizing solar energy utilization, broadening the spectral response, and improving device efficiency.

[0079] The composite layer 130a not only serves to modify the interface between the bottom cell 120ac and the top cell 110a, but also improves the passivation and interfacial contact properties of the bottom cell 120a that may be affected by the fabrication of the top cell 110a. Specifically, the electrons and holes in the top cell 110a can recombine in the composite layer 130a, maximizing the consistency between the currents of the bottom cell 120a and the top cell 110a. Furthermore, the composite layer 130a exhibits a certain degree of longitudinal conductivity, facilitating charge transport. For example, a conductive oxide film can be used as the composite layer 130a. For example, the composite layer 130a can be made of one or a combination of at least two of ITO (Indium Tin Oxide), IWO (Tungsten-doped Indium Oxide), ICO (Cerium-doped Indium Oxide), IZO (Indium Zinc Oxide), AZO (Al-doped Zinc Oxide), GZO (Gallium Zinc Oxide), SnO2, or TiO2. The composite layer 130a can have a single-layer or multi-layer structure. The material of the single-layer structure may include one or more combinations of the aforementioned materials, and the multi-layer structure may be a stacked structure of an ITO layer and an IWO layer, which is not specifically limited here.

[0080] Exemplarily, the thickness of the composite layer 130a is 10 nm to 40 nm. For example, the thickness of the composite layer 130a can be 10 nm, 15 nm, 20 nm, 26 nm, 30 nm, 35 nm, or 40 nm. Of course, the thickness can also be any other value within the range of 10 nm to 40 nm, and is not specifically limited here.

[0081] The substrate 121 is used to receive incident light and generate photogenerated carriers. The substrate 121 can be selected according to actual needs. Exemplarily, the substrate 121 can be a silicon substrate. The doping type of the substrate 121 is not specifically limited. For example, the substrate 121 can be an N-type doped silicon substrate, or it can be a P-type doped silicon substrate, without specific limitation. In the embodiment of the present application, the substrate 121 can be an N-type single crystal silicon wafer. Exemplarily, the thickness of the substrate 121 is 120 μm to 240 μm. For example, the thickness of the substrate 121 can be 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 200 μm, 220 μm, or 240 μm. Of course, it can also be any other value within the range of 120 μm to 240 μm, without specific limitation here.

[0082] The substrate 121 has a first surface m1 and a second surface m2, arranged opposite each other along a first direction F1. The first surface m1 is the light-receiving surface, and the second surface m2 is the backlight surface. It will be understood that the light-receiving surface and the backlight surface are relative terms. The light-receiving surface specifically refers to the surface of the substrate in the stacked solar cell 100a or photovoltaic module that is primarily illuminated by sunlight. The light-receiving surface is typically provided with a velvet structure, which increases the light absorption area, improves the photocurrent, and contributes to improving the efficiency of the cell.

[0083] The first tunneling layer 1221a is used to achieve interface passivation of the first surface m1 of the substrate 121, which has the effect of chemical passivation. Specifically, by saturating the dangling bonds of the first surface m1 of the substrate 121, the interface defect state density of the first surface m1 of the substrate 121 is reduced, thereby reducing the recombination center of the first surface m1 of the substrate 121 to reduce the carrier recombination rate. Among them, the material of the tunneling oxide layer can be a dielectric material. For example, the material of the first tunneling layer 1221a can be at least one of silicon oxide, magnesium fluoride, silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide. In an embodiment of the present application, the first tunneling layer 1221a can be formed by low pressure chemical vapor deposition (LPCVD). Of course, the first tunneling layer 1221a can also be obtained by other processes such as thermal oxidation process, plasma oxidation process or nitric acid oxidation process, which are not specifically limited here.

[0084] Exemplarily, the dimension of the first tunneling layer 1221a along the first direction F1, i.e., the thickness of the first tunneling layer 1221a, can be 0.5 nm to 3 nm. For example, the thickness of the first tunneling layer 1221a can be 0.5 nm, 1 nm, 2 nm, or 3 nm. Of course, any other value within the range of 0.5 nm to 3 nm is also possible, and is not specifically limited herein. By controlling the thickness of the first tunneling layer 1221a, a certain passivation effect can be achieved while suppressing a reduction in fill factor caused by contact resistance.

[0085] The doping element of the first doped conductive layer 1222a is adapted to the conductivity type of the doping element of the substrate 121. For example, when the substrate 121 is an N-type substrate, the doping element of the substrate 121 may be phosphorus and / or antimony. The doping element of the first doped conductive layer 1222a is phosphorus. For another example, when the substrate 121 is a P-type substrate, the doping element of the first doped conductive layer 1222a is boron. In an embodiment of the present application, the first doped conductive layer 1222a is formed by doping amorphous silicon, microcrystalline silicon, polycrystalline silicon, etc. with an N-type doping element. Exemplarily, the first doped conductive layer 1222a is a phosphorus-doped polycrystalline silicon layer. At this time, the stacked first tunneling layer 1221a and the first doped conductive layer 1222a together form a passivation contact structure, which provides good surface passivation for the first surface m1 of the substrate 121.

[0086] Exemplarily, the dimension of the first doped conductive layer 1222a along the first direction F1, that is, the thickness of the first doped conductive layer 1222a, is 30 nm to 300 nm. For example, the thickness of the first doped conductive layer 1222a can be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 100 nm, 150 nm, 200 nm, 230 nm, 280 nm, or 300 nm. Of course, the thickness can also be any other value within the range of 30 nm to 300 nm, and is not specifically limited here.

[0087] The orthographic projections of the top cell 110a and the bottom cell 120a on a reference plane E, which is a plane perpendicular to the first direction F1, overlap. The orthographic projection of the first passivation contact layer 122a on the reference plane E lies within the overlapping projections, and the area of ​​the orthographic projection of the first passivation contact layer 122a on the reference plane E is smaller than the area of ​​the overlapping projections. The portion of the substrate 121 surface facing the top cell 110a that is exposed through the first passivation contact layer 122a is a first sub-surface m11. The first passivation contact layer 122a has a first target surface t1 that is not in contact with the substrate 121 surface facing the top cell 110a and is located within the tandem solar cell 100a. The tandem solar cell 100a further includes a first passivation layer 140 disposed on the first sub-surface m11 and the first target surface t1. The composite layer 130a and the first passivation layer 140 are in contact with each other on their facing surfaces.

[0088] Combined with reference Figure 2 and Figure 3 , Figure 2 Schematic diagram of the cross-sectional structure of the substrate 121, the first passivation contact layer 122a, the first passivation layer 140 and the composite layer 130a in some embodiments of the present application. Figure 3Schematic diagram of the relationship between the first projection y1 and the second projection y2 in some embodiments of the present application. The orthographic projection of the first passivation contact layer 122a on the reference plane E is the first projection y1, and the overlapping projection is the second projection y2. The first projection y1 is within the range of the second projection y2, and the area of ​​the first projection y1 is smaller than the area of ​​the second projection y2. Figure 2 and Figure 3 , the second direction F2 and the third direction F3 are schematically shown as the length and width directions of the stacked solar cell 100a, the first direction F1, the second direction F2 and the third direction F3 are perpendicular to each other, and the second direction F2 and the third direction F3 are parallel to the reference plane E.

[0089] It can be understood that since the area of ​​the first projection y1 is smaller than the area of ​​the second projection y2, the first passivation contact layer 122a does not completely cover the side surface of the substrate 121 facing the top battery unit 110a, that is, the first passivation contact layer 122a does not completely cover the first surface m1 of the substrate 121. The portion of the first surface m1 that is not covered by the first passivation contact layer 122a is the first sub-surface m11. The surface of the first passivation contact layer 122a includes a surface in contact with the substrate 121 (recorded as the bottom surface), a surface set away from the substrate 121 (recorded as the top surface), and a surface connecting the "surface in contact with the substrate 121" and the "surface set away from the substrate 121" (recorded as the side surface). According to the structure of the first passivation contact layer 122a, the side surface of the first passivation contact layer 122a may be entirely located within the stacked solar cell 100a, or a portion may be located within the stacked solar cell 100a, and the other portion may not be located within the stacked solar cell 100a. For example, Figure 1 and Figure 2 For example, the case where the entire side surface of the first passivation contact layer 122a is located within the tandem solar cell 100a is illustrated. If a portion of the side surface of the first passivation contact layer 122a is not located within the tandem solar cell 100a, the side surface of this portion can be flush with the side surface of the tandem solar cell 100a. That is, the first target surface t1 includes the aforementioned top surface of the first passivation contact layer 122a and the side surface of the first passivation contact layer 122a located within the tandem solar cell.

[0090] For example, using an N-type substrate as an example, a low-pressure chemical vapor deposition (LPCVD) method can be used to form an initial first tunneling layer on the first surface m1 of the substrate 121. Specifically, oxygen can be introduced under heating conditions, causing the silicon on the first surface m1 of the substrate 121 to react with the oxygen to form silicon oxide, thereby forming the initial first tunneling layer. Of course, other processes such as thermal oxidation, plasma oxidation, or nitric acid oxidation can also be used to form the initial first tunneling layer, which is not specifically limited here. Subsequently, phosphorus diffusion and oxidation annealing can be performed on the amorphous silicon layer on the first surface m1 of the substrate 121 in a high-temperature diffusion furnace to form an N-type polycrystalline silicon layer, i.e., the initial first doped conductive layer. The initial first doped conductive layer and the initial first tunneling layer constitute the initial first passivation contact layer. Next, a laser etching process is used to remove portions of the initial first passivation contact layer to form the first passivation contact layer 122a. Of course, the first passivation contact layer 122a can also be formed by using a mask, which is not specifically limited here.

[0091] During the formation of the first passivation contact layer 122a, the use of a laser etching process carries the risk of thermal damage, mechanical stress damage, and plasma damage. The use of a mask process carries the risk of etching damage and thermal stress damage, thereby risking damage to the first passivation contact layer 122a. Furthermore, both etching ion bombardment and laser thermal stress ultimately cause silicon atoms on the surface of the first passivation contact layer 122a to lose neighboring bonds, forming dangling bonds. Dangling bonds may exist in undamaged areas of the first passivation contact layer 122a due to the inability of silicon atoms at grain boundaries to fully form tetrahedral bonds due to different grain orientations, or due to differences in the covalent radius between dopant atoms and silicon atoms, which may cause local bond distortion and form dangling bonds. Therefore, dangling bonds in both damaged and undamaged areas can capture electrons or holes, forming fixed charges or trapped charges, leading to device parameter drift. Furthermore, the dangling bonds in damaged and undamaged areas of the first passivation contact layer 122a have minimal chemical activity differences and similar electronic structures. Thus, by providing the first passivation layer 140, the hydrogen content or charge density in the first passivation layer 140 can be controlled, and the damaged and undamaged portions of the surface of the first passivation contact layer 122a can be passivated simultaneously. It is understood that stress may be generated at the interface between the damaged and undamaged portions of the first passivation contact layer 122a due to differences in thermal expansion coefficients. Therefore, by providing the first passivation layer 140, not only can defects be more uniformly controlled, but the boundary stress at the interface between the damaged and undamaged portions can also be improved, thereby improving the consistency and reliability of the first passivation contact layer 122a.

[0092] In the embodiment of the present application, by configuring the area of ​​the positive projection of the first passivation contact layer 122a on the reference plane E to be smaller than the area of ​​the overlapping projections of the top battery cell 110a and the bottom battery cell 120a, the first passivation contact layer 122a covers a partial area of ​​the surface of the substrate 121 facing the top battery cell 110a, thereby not only reducing the optical parasitic absorption of the first doped conductive layer 1222a, improving the optical loss of the battery, and thus increasing the short-circuit current of the battery, but also increasing the physical contact area and electrical connection efficiency of the interface, reducing the resistance between the interfaces, and thus facilitating the conduction and collection of minority carriers by the battery, thereby improving the fill factor of the battery. At the same time, because the first passivation layer 140 is provided on the first sub-surface m11 exposed by the first passivation contact layer 122a and the first target surface t1 of the first passivation contact layer 122a, the surfaces of the composite layer 130a and the first passivation layer 140 facing each other are in contact with each other. This not only reduces film defects in the first passivation contact layer 122a, reduces recombination centers, and improves the consistency and reliability of the first passivation contact layer 122a, but also reduces the potential energy barrier between film layers, thereby facilitating the conduction and collection of minority carriers in the battery, thereby improving the battery's open circuit voltage and fill factor. Therefore, through the interaction between the first passivation contact layer 122a and the first passivation layer 140, the efficiency of the battery can be improved.

[0093] According to some embodiments of this application, please continue to refer to Figures 1 to 3 The first passivation contact layer 122a includes a plurality of first passivation contact portions 1220a arranged at intervals. That is, all first passivation contact portions 1220a are arranged at intervals, all first passivation contact portions 1220a are independently arranged, and all first passivation contact portions 1220a define intervals.

[0094] Since the first passivation contact portion 1220 a is not provided at the interval, the optical parasitic absorption of the first doped conductive layer 1222 a can be further reduced.

[0095] According to some embodiments of this application, please continue to refer to Figures 1 to 3 At least some of the first passivation contact portions 1220a are spaced apart along the second direction F2, and the first passivation contact portions 1220a extend longitudinally along the third direction F3. The second direction F2 and the third direction F3 intersect each other and are both perpendicular to the first direction F1.

[0096] The first passivation contact portion 1220a is longitudinally extended along the third direction F3, that is, the first passivation contact portion 1220a is substantially arranged in a strip shape. For example, in combination with the contents illustrated in some of the aforementioned embodiments, the second direction F2 and the third direction F3 can be perpendicular to each other. For example, some of the first passivation contact portions 1220a can be arranged at intervals along the second direction F2, or all of the first passivation contact portions 1220a can be arranged at intervals along the second direction F2. Figure 2 and Figure 3 As an example, a situation where all the first passivation contact portions 1220a are arranged at intervals along the second direction F2 is illustrated.

[0097] In this way, the optical parasitic absorption of the first doped conductive layer 1222a can be reduced while the current is reduced to a smaller extent, which is beneficial to improving the fill factor of the battery and thus improving the efficiency of the battery.

[0098] According to some embodiments of this application, please refer to Figure 4 , Figure 4 This is a schematic top view of the structure of the substrate 121 and the first passivation contact layer 122b in other embodiments of the present application. The first passivation contact layer 122b includes a plurality of first passivation contact portions 1220b. All first passivation contact portions 1220b are arranged in rows and columns along the second direction F2 and the third direction F3. When the second direction F2 and the third direction F3 are perpendicular to each other, all first passivation contact portions 1220b are arranged in a rectangular array.

[0099] For example, the cross section of the first passivation structure perpendicular to the first direction F1 may be rectangular, circular, triangular or other shapes, which are not specifically limited here. Figure 4 As an example, the case where the cross section of the first passivation structure perpendicular to the first direction F1 is a rectangle is illustrated.

[0100] At this time, compared with the strip-shaped first passivation contact portion 1220a shown in some of the above embodiments, Figure 4 In the illustrated case, it is further advantageous to reduce the optical parasitic absorption of the first doped conductive layer 1222a. Of course, the strip-shaped first passivation contact portion 1220b illustrated in some of the aforementioned embodiments can enable the battery to have a higher fill factor.

[0101] According to some embodiments of this application, please refer to Figure 5 , Figure 5 Schematic diagram of a top view of the substrate 121 and the first passivation contact layer 122c in some other embodiments of the present application. The first passivation contact layer 122c is provided with a plurality of first through holes k1 penetrating the first passivation contact layer 122c along the first direction F1.

[0102] The first through hole k1 penetrates the first passivation contact layer 122c. That is, the first through hole k1 can expose a portion of the first surface m1 of the substrate 121 that is located opposite the first through hole k1. In this case, combined with the situations illustrated in some of the aforementioned embodiments, the side surface of the first passivation contact layer 122c located within the stacked solar cell can be understood as the inner wall of the first through hole k1.

[0103] For example, the cross section of the first through hole k1 perpendicular to the first direction F1 may be rectangular, circular, triangular or other shapes, which are not specifically limited here. Figure 5 For example, the cross section of the first through hole k1 perpendicular to the first direction F1 is a rectangular shape. The arrangement of the first through hole k1 can be understood and implemented with reference to the arrangement of the first passivation contact portion 1220a and the first passivation contact portion 1220b illustrated in some of the aforementioned embodiments, and is not specifically limited here. Figure 5 In the illustrated embodiment, the plurality of first through holes k1 are arranged in a rectangular array.

[0104] In this way, the optical absorption of the first doped conductive layer 1222 a can be reduced by forming the through hole.

[0105] According to some embodiments of this application, please refer to Figure 6 , Figure 6 This is a schematic top view of the structure of the substrate 121 and the first passivation contact layer 122d in some further embodiments of the present application. The first passivation contact layer 122d includes multiple first sub-sections 12201 and multiple second sub-sections 12202. The first sub-sections 12201 extend along the fourth direction F4 and are spaced apart along the fifth direction F5. The second sub-sections 12202 are spaced apart along the fourth direction F4. Each second sub-section 12202 is connected to any one of the first sub-sections 12201. The fourth direction F4 and the fifth direction F5 intersect with each other and are both perpendicular to the first direction F1.

[0106] For example, the fourth direction F4 and the fifth direction F5 are perpendicular to each other. Figure 6 For example, the fourth direction F4 may coincide with the third direction F3, and the fifth direction F5 may coincide with the second direction F2.

[0107] The first sub-section 12201 and the second sub-section 12202 are generally arranged in a strip shape. When each second sub-section 12202 is connected to any one of all the first sub-sections 12201, the first sub-section 12201 and the second sub-section 12202 generally form a grid structure. Figure 4 The situation shown is beneficial for increasing the contact area while reducing shading, thereby improving the fill factor of the battery.

[0108] It should be noted that the structure of the first passivation contact layer may include, but is not limited to, the configurations illustrated in some of the above embodiments, and may also be other configurations, which are not specifically limited herein. It is understood that when the configurations illustrated in some of the above embodiments are used to form the first passivation contact layer, in addition to the advantages illustrated in some of the above embodiments, it is also advantageous to manufacture the first passivation contact layer. In addition, because the first passivation contact layer has good lateral conductivity, compared to the first passivation contact layer that completely covers the first surface m1 of the substrate 121, the first passivation contact layer provided in the embodiment of the present application not only has a certain charge transfer and collection capability, but also can reduce parasitic absorption of light, thereby increasing the short-circuit current.

[0109] According to some embodiments of this application, please continue to refer to Figure 1 and Figure 2 The material of the first passivation layer 140 includes metal oxide, non-metal nitride or non-metal oxynitride.

[0110] For example, the metal oxide may be made of aluminum oxide, yttrium oxide, ytterbium oxide, silicon oxide, or the like. The non-metallic nitride may be made of silicon nitride, aluminum nitride, or the like. The non-metallic oxynitride may be made of silicon oxynitride, aluminum oxynitride, or the like. These are not specifically limited herein.

[0111] When the material of the first passivation layer 140 includes a metal oxide, the metal oxide can provide a high-density negative charge, thereby achieving a field passivation effect. When the material of the first passivation layer 140 includes a non-metallic nitride or a non-metallic oxynitride, the non-metallic nitride or non-metallic oxynitride can provide hydrogen atoms, which can diffuse to the surface of the first passivation contact layer to passivate dangling bonds, thereby achieving chemical passivation.

[0112] According to some embodiments of this application, please continue to refer to Figure 1 and Figure 2 The material of the first passivation layer 140 includes metal oxide, and the thickness of the first passivation layer 140 is 1nm to 50nm; or, the material of the first passivation layer 140 includes non-metal nitride or non-metal nitride oxide, and the thickness of the first passivation layer 140 is 50nm to 100nm.

[0113] The thickness of the first passivation layer 140 refers to the dimension extending in a direction perpendicular to the surface formed by the first target surface t1 and the first sub-surface m11 based on the undulations of the surface formed by the first target surface t1 and the first sub-surface m11. It can be understood that since the surface formed by the first target surface t1 and the first sub-surface m11 is a surface with undulations, there are multiple directions perpendicular to the surface formed, which can be specifically determined according to the shape of the corresponding parts. For example, in combination with the contents illustrated in some of the aforementioned embodiments, Figure 2For example, the thickness of the portion of the first passivation layer 140 located on the top surface of the first passivation contact layer 122a is the size of the portion along the first direction F1, the thickness of the portion of the first passivation layer 140 located on the first sub-surface m11 is the size of the portion along the first direction F1, and the thickness of the portion of the first passivation layer 140 located on the side surface of the first passivation contact layer 122a is the size of the portion along the second direction F2. The first direction F1 is perpendicular to the top surface of the first passivation contact layer 122a, and the second direction F2 is perpendicular to the side surface of the first passivation contact layer 122a. For example, Figure 2 For example, it is illustrated that the thickness of the portion of the first passivation layer 140 located on the first sub-surface m11 is the first size h1.

[0114] For example, when the material of the first passivation layer 140 includes a metal oxide, the thickness of the first passivation layer 140 may be 1 nm, 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 45 nm, or 50 nm. Of course, it may also be any other value within the range of 1 nm to 50 nm, and is not specifically limited here. When the material of the first passivation layer 140 includes a non-metallic nitride or a non-metallic oxynitride, the thickness of the first passivation layer 140 may be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 77 nm, 80 nm, 90 nm, or 100 nm. Of course, it may also be any other value within the range of 50 nm to 100 nm, and is not specifically limited here.

[0115] In this way, by controlling the thickness of the first passivation layer 140 , the first passivation layer 140 can have a certain passivation effect and a certain carrier transmission capability.

[0116] According to some embodiments of this application, please refer to Figure 7 and Figure 8 , Figure 7 is a schematic cross-sectional view of a stacked solar cell 100b in some other embodiments of the present application. Figure 8 for Figure 7 FIGURE 1 shows a schematic cross-sectional structure diagram of a composite layer 130b in a tandem solar cell 100b. Composite layer 130b includes a first portion 131 and a second portion 132. The orthographic projection of first portion 131 on reference plane E overlaps with the orthographic projection of first passivation contact layer 122a on reference plane E. The thickness of the portion of second portion 132 not in contact with first passivation contact layer 122a is less than the thickness of first portion 131.

[0117] Exemplary, with reference to Figure 8The thickness of the first portion 131 is the first thickness d1, the portion of the second portion 132 that is not in contact with the first passivation contact layer 122a is the target portion 1321, and the thickness of the target portion 1321 is the second thickness d2, which is less than the first thickness d1. Figure 8 In the illustrated embodiment, the thickness of the first portion 131 is the dimension of the first portion 131 along the first direction F1, the thickness of the target portion 1321 is the dimension of the second portion 132 along the first direction F1, and the thickness of the second portion 132 excluding the target portion 1321 is the dimension of the second portion 132 along the second direction F2. The thickness of the composite layer 130b can be understood with reference to the thickness of the first passivation layer 140 illustrated above and is not further described here.

[0118] For example, the composite layer 130b can be thinned by laser etching to form the first portion 131 and the second portion 132. Alternatively, the first portion 131 and the second portion 132 can be formed by double evaporation using a mask, without specific limitation herein. The thickness ranges corresponding to the various portions of the composite layer 130b can refer to the thickness of the composite layer 130b illustrated in some of the aforementioned embodiments, and are not further elaborated here. It is sufficient that the thickness of the portion of the second portion 132 not in contact with the first passivation contact layer 122a is less than the thickness of the first portion 131.

[0119] This not only reduces optical parasitic absorption of the composite layer 130b but also helps maintain good lateral charge transfer. Furthermore, because the thicker first portion 131 of the composite layer 130b corresponds to the first passivation contact layer 122a, and therefore to the related electrode structures (e.g., the first electrode 180 and the second electrode 190) described later, this facilitates longitudinal charge transfer, thereby increasing short-circuit current.

[0120] Of course, in Figure 1 and Figure 2 In the composite layer 130a shown, each portion of the composite layer 130a has the same thickness. Figure 7 and Figure 8 The composite layer 130b shown is different. No specific limitation is given here. It is understood that Figure 7 and Figure 8 In the case of the illustrated composite layer 130 b , the optical parasitic absorption of the tandem solar cell can be further reduced by reducing the optical parasitic absorption of the composite layer 130 b .

[0121] According to some embodiments of this application, please refer to Figure 9 and Figure 10 , Figure 9 Schematic diagram of the cross-sectional structure of a stacked solar cell 100c in some other embodiments of the present application, Figure 10 for Figure 9 The cross-sectional structure diagram of the composite layer 130b and the second passivation layer 150 in the stacked solar cell 100c is shown in the figure. The stacked solar cell 100c also includes a second passivation layer 150, which is arranged on the side surface of the composite layer 130b away from the bottom battery unit 120a.

[0122] For example, the oxygen defect points of the composite layer 130 b may be eliminated by thermal annealing, and then the surface of the composite layer 130 b may be passivated by the second passivation layer 150 .

[0123] In this way, by setting the second passivation layer 150, not only can the surface defects of the composite layer 130b be passivated to reduce the recombination center, but it can also cooperate with the first passivation layer 140 so that the composite layer 130b is located between the first passivation layer 140 and the second passivation layer 150 to form an alternating structure, which can further reduce the potential energy barrier in the stacked solar cell, and thus be beneficial to the rapid transmission of minority carriers as a whole, thereby improving the open circuit voltage, fill factor and short-circuit current of the stacked solar cell, and thus helping to improve the efficiency of the battery.

[0124] According to some embodiments of this application, please continue to refer to Figure 9 and Figure 10 , the second passivation layer 150 is configured as a monomolecular layer.

[0125] Exemplary materials for the monolayer include one or more of [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), and [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz). Thermal annealing can eliminate oxygen defects in the composite layer 130b. Phosphonic acid (H2PO3) molecules, for example, can then preferentially adsorb oxygen vacancies on the surface of the composite layer 130b, saturating dangling bonds and reducing the interface state density. Alternatively, a molecular layer containing fluorine, carboxyl, or phosphonic acid groups can be used to form an interface dipole on the surface of the composite layer 130b, thereby increasing the work function.

[0126] In this way, by configuring the second passivation layer 150 as a monomolecular layer, it is beneficial to improve the carrier transmission efficiency and interface stability.

[0127] Of course, in some other embodiments, the second passivation layer 150 may also be made of other materials. Since the second passivation layer 150 cooperates with the composite layer 130b, configuring the second passivation layer 150 as a monolayer will have more advantages as described above.

[0128] According to some embodiments of this application, please continue to refer to Figure 10, the thickness of the second passivation layer 150 is 0.3 nm to 2 nm.

[0129] For example, the thickness of the second passivation layer 150 may be 0.3 nm, 0.5 nm, 1 nm, 1.5 nm, 1.8 nm, 1.9 nm, or 2 nm.

[0130] It can be understood that since the second passivation layer 150 varies with the surface undulation of the composite layer 130b, the understanding of the thickness of the second passivation layer 150 can refer to the understanding of the thickness of the composite layer 130b shown above, and will not be repeated here. Figure 9 and Figure 10 As an example, it is illustrated that the thickness of the portion of the second passivation layer 150 opposite to the first passivation contact layer 122a along the first direction F1 is the second size h2.

[0131] In this way, by controlling the thickness of the second passivation layer 150 , the second passivation layer 150 can have a certain passivation effect and a certain carrier transmission capability.

[0132] According to some embodiments of this application, please continue to refer to Figure 1 、 Figure 7 and Figure 9 The bottom battery cell 120a further includes a second passivation contact layer 123a, which includes a second tunneling layer 1231a and a second doped conductive layer 1232a stacked on a surface of the substrate 121 facing away from the top battery cell 110a.

[0133] The understanding of the second tunneling layer 1231a and the second doped conductive layer 1232a can refer to the understanding of the first tunneling layer 1221a and the first doped conductive layer 1222a shown in the above diagram, and will not be repeated here. In an embodiment of the present application, the second doped conductive layer 1232a can be formed by doping amorphous silicon, microcrystalline silicon, polycrystalline silicon, etc. with P-type doping elements. Exemplarily, the second doped conductive layer 1232a is a boron-doped polycrystalline silicon layer. At this time, the stacked second tunneling layer 1231a and the second doped conductive layer 1232a together form a passivation contact structure, which provides good surface passivation for the second surface m2 of the substrate 121.

[0134] Exemplarily, the dimension of the second doped conductive layer 1232a along the first direction F1, that is, the thickness of the second doped conductive layer 1232a, is 50 nm to 400 nm. For example, the thickness of the second doped conductive layer 1232a can be 50 nm, 60 nm, 70 nm, 80 nm, 100 nm, 120 nm, 200 nm, 260 nm, 350 nm, 390 nm, or 400 nm. This is not specifically limited herein. Of course, it can also be any other value within the range of 50 nm to 400 nm, and this is not specifically limited herein.

[0135] According to some embodiments of this application, please continue to refer to Figure 1 、 Figure 7 and Figure 9 The bottom cell 120a further includes a third passivation layer 160a, which is disposed on a surface of the second doped conductive layer 1232a facing away from the second tunneling layer 1231a. The third passivation layer 160a can be a single-layer structure or a multi-layer structure. The material of the third passivation layer 160a includes a metal oxide, a non-metallic nitride, or a non-metallic oxynitride. The third passivation layer 160a can serve as a passivation layer.

[0136] According to some embodiments of this application, please refer to Figure 11 and Figure 12 , Figure 11 is a schematic cross-sectional view of a stacked solar cell 100d in some other embodiments of the present application. Figure 12 for Figure 11 The schematic cross-sectional view of a portion of the structure of a tandem solar cell 100d is shown in FIG. The bottom cell 120b further includes a second passivation contact layer 123b. The second passivation contact layer 123b comprises a second tunneling layer 1231a and a second doped conductive layer 1232a stacked on a surface of the substrate 121 facing away from the top cell 110a. The orthographic projection of the second passivation contact layer 123b on the reference plane E is within the overlapping projection range, and the area of ​​the orthographic projection of the second passivation contact layer 123b on the reference plane E is smaller than the area of ​​the overlapping projection.

[0137] That is, the second tunneling layer 1231 b is disposed on the second surface m2 of the substrate 121 , and the second doped conductive layer 1232 b is disposed on a side surface of the second tunneling layer 1231 b away from the substrate 121 .

[0138] The relationship between the orthographic projection and the overlapping projection of the second passivation contact layer 123b on the reference plane E, the related manufacturing methods, and the related embodiments can be understood by referring to the relationship between the orthographic projection and the overlapping projection of the first passivation contact layer 122a on the reference plane E, the related manufacturing methods, and the related embodiments illustrated in some of the aforementioned embodiments, and will not be repeated here. The difference is that the first doped conductive layer 1222a and the second doped conductive layer 1232a have different doping types.

[0139] In this way, by configuring the area of ​​the positive projection of the second passivation contact layer 123b on the reference plane E to be smaller than the area of ​​the overlapping projections of the top battery cell 110a and the bottom battery cell 120b, the second passivation contact layer 123b covers a partial area of ​​the surface of the side of the substrate 121 away from the top battery cell 110a, thereby not only reducing the optical parasitic absorption of the second doped conductive layer 1232b, improving the optical loss of the battery, and thus increasing the short-circuit current of the battery, but also increasing the physical contact area and electrical connection efficiency of the interface, reducing the resistance between the interfaces, which is beneficial to the conduction and collection of minority carriers by the battery, and thus improving the fill factor of the battery.

[0140] It should be noted that, since the second passivation contact layer 123b has good lateral conductivity, compared with the second passivation contact layer 123a that completely covers the second surface m2 of the substrate 121, the second passivation contact layer 123b provided in the embodiment of the present application not only has a certain charge transfer and collection capability, but also can reduce light parasitic absorption, thereby increasing the short-circuit current.

[0141] According to some embodiments of this application, please continue to refer to Figure 11 and Figure 12 The second passivation contact layer 123b includes a plurality of second passivation contact portions 1230 arranged at intervals. That is, all the second passivation contact portions 1230 are arranged at intervals, all the second passivation contact portions 1230 are independently arranged, and all the second passivation contact portions 1230 define intervals.

[0142] Since the second passivation contact portion 1230 is not provided at the interval, the optical parasitic absorption of the second doped conductive layer 1232 b can be further reduced.

[0143] It should be noted that the relevant implementations and advantages of the second passivation contact portion 1230 can be combined with the implementations and advantages of the first passivation contact portion 1220a and the first passivation contact portion 1220b illustrated in some of the aforementioned embodiments, and will not be repeated here.

[0144] According to some embodiments of this application, please refer to Figure 13 , Figure 13This is a schematic top view of the structure of the substrate 121 and the second passivation contact structure in some other embodiments of the present application. The second passivation contact layer 123c is provided with a plurality of second through holes k2 penetrating the second passivation contact layer 123c along the first direction F1.

[0145] The second through hole k2 penetrates the second passivation contact layer 123 c . That is, the second through hole k2 may expose a portion of the second surface m2 of the substrate 121 opposite to the second through hole k2 .

[0146] For example, the cross section of the second through hole k2 perpendicular to the first direction F1 can be rectangular, circular, triangular or other shapes, which are not specifically limited here. Figure 13 For example, the cross section of the second through hole k2 perpendicular to the first direction F1 is a rectangular shape. The arrangement of the second through hole k2 can be understood and implemented with reference to the arrangement of the second passivation contact portion 1230 illustrated in some of the aforementioned embodiments, and is not specifically limited here. Figure 13 In the illustrated case, the plurality of second through holes k2 are arranged in a rectangular array.

[0147] In this way, the optical absorption of the second doped conductive layer 1232 b can be reduced by forming the through hole.

[0148] According to some embodiments of this application, please continue to refer to Figure 11 and Figure 12 The portion of the substrate 121 surface facing away from the top cell 110a that is exposed through the second passivation contact layer 123b is a second sub-surface m21. The second passivation contact layer 123b has a second target surface t2 that is not in contact with the substrate 121 surface facing away from the top cell 110a and is located within the tandem solar cell 100d. The tandem solar cell 100d further includes a third passivation layer 160b disposed on the second sub-surface m21 and the second target surface t2.

[0149] By referring to the formation process of the first passivation contact layer, the damage risk generated during the formation of the second passivation contact layer 123b can be understood with reference to the damage risk of the first passivation contact layer. Therefore, by providing the third passivation layer 160b, not only can defects be more uniformly controlled, but the boundary stress at the junction of damaged and undamaged areas can also be improved, thereby improving the consistency and reliability of the second passivation contact layer 123b.

[0150] It should be noted that the understanding of the second target surface t2 can be understood with reference to the first target surface t1, and will not be repeated here.

[0151] According to some embodiments of this application, please continue to refer to Figure 11 and Figure 12The material of the third passivation layer 160b includes metal oxide, non-metal nitride or non-metal oxynitride.

[0152] For example, the metal oxide may be made of aluminum oxide, yttrium oxide, ytterbium oxide, silicon oxide, or the like. The non-metallic nitride may be made of silicon nitride, aluminum nitride, or the like. The non-metallic oxynitride may be made of silicon oxynitride, aluminum oxynitride, or the like. These are not specifically limited herein.

[0153] When the material of the third passivation layer 160b includes a metal oxide, the metal oxide can provide a high-density negative charge, thereby achieving a field passivation effect. When the material of the third passivation layer 160b includes a non-metallic nitride or a non-metallic oxynitride, the non-metallic nitride or non-metallic oxynitride can provide hydrogen atoms, which can diffuse to the surface of the third passivation contact layer to passivate dangling bonds, thereby achieving chemical passivation.

[0154] According to some embodiments of this application, please continue to refer to Figure 11 and Figure 12 The material of the third passivation layer 160b includes metal oxide, and the thickness of the third passivation layer 160b is 1nm to 50nm; or, the material of the third passivation layer 160b includes non-metal nitride or non-metal nitride oxide, and the thickness of the third passivation layer 160b is 50nm to 100nm.

[0155] The thickness of the third passivation layer 160b can be understood in conjunction with the thickness of the first passivation layer 140, and will not be described in detail here. Figure 12 For example, it is illustrated that the thickness of the portion of the third passivation layer 160b located on the second sub-surface m21 is a third size h3.

[0156] For example, when the material of the third passivation layer 160b includes a metal oxide, the thickness of the third passivation layer 160b can be 1 nm, 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 45 nm, or 50 nm. Of course, it can also be any other value within the range of 1 nm to 50 nm, and is not specifically limited here. When the material of the third passivation layer 160b includes a non-metallic nitride or a non-metallic oxynitride, the thickness of the third passivation layer 160b can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 77 nm, 80 nm, 90 nm, or 100 nm. Of course, it can also be any other value within the range of 50 nm to 100 nm, and is not specifically limited here.

[0157] In this way, by controlling the thickness of the third passivation layer 160 b , the third passivation layer 160 b can have a certain passivation effect and a certain carrier transmission capability.

[0158] According to some embodiments of this application, please refer to Figure 14 and Figure 15 , Figure 14 Schematic diagram of the cross-sectional structure of a stacked solar cell 100e in some other embodiments of the present application, Figure 15 for Figure 14 In the schematic cross-sectional view of a portion of the structure of a tandem solar cell 100e, shown in FIG, the bottom cell 120c further includes a doped layer 124a disposed on a surface of the substrate 121 facing away from the top cell 110a. The orthographic projection of the doped layer 124a on the reference plane E is within the overlapping projection range, and the area of ​​the orthographic projection of the doped layer 124a on the reference plane E is smaller than the area of ​​the overlapping projection.

[0159] The doping type of the doping layer 124a is different from the doping type of the first doped conductive layer 1222a. For example, the doping type of the first doped conductive layer 1222a is N-type, and the doping type of the doping layer 124a is P-type.

[0160] Exemplarily, the doping layer 124a includes a doping diffusion layer. For example, the second surface m2 of the substrate 121 can be diffused in a diffusion furnace containing a P-type doping element to form a doping diffusion layer, and the doping layer 124a can be a boron diffusion layer. Figure 14 and Figure 15 As an example, the situation where the second surface m2 of the substrate 121 is subjected to diffusion treatment to form the doping layer 124a is illustrated.

[0161] The relationship between the orthographic projection and the overlapping projection of the doped layer 124a on the reference plane E, the related manufacturing methods, and the related implementation methods can be understood by referring to the relationship between the orthographic projection and the overlapping projection of the first passivation contact layer on the reference plane E, the related manufacturing methods, and the related implementation methods illustrated in some of the aforementioned embodiments, and will not be repeated here. The difference lies in the difference between the formation process of the doped layer 124a and the formation process of the first passivation contact layer. However, the configuration method for ensuring that the area of ​​the orthographic projection of the doped layer 124a on the reference plane E is smaller than the area of ​​the overlapping projection can be implemented by referring to the first passivation contact layer, and will not be repeated here.

[0162] In this way, by configuring the area of ​​the positive projection of the doping layer 124a on the reference plane E to be smaller than the area of ​​the overlapping projections of the top battery cell 110a and the bottom battery cell 120c, the doping layer 124a covers a partial area of ​​the surface of the side of the substrate 121 away from the top battery cell 110a, thereby not only reducing the optical parasitic absorption of the doping layer 124a, improving the optical loss of the battery, and thus increasing the short-circuit current of the battery, but also increasing the physical contact area and electrical connection efficiency of the interface, reducing the resistance between the interfaces, and thus facilitating the conduction and collection of minority carriers by the battery, thereby improving the fill factor of the battery.

[0163] According to some embodiments of this application, please continue to refer to Figure 14 and Figure 15 The doping layer 124a includes a plurality of doping portions 1240 arranged at intervals. That is, all the doping portions 1240 are arranged at intervals, all the doping portions 1240 are independently arranged, and all the doping portions 1240 define intervals.

[0164] Since the doped portion 1240 is not provided at the interval, the optical parasitic absorption of the doped layer 124 a can be further reduced.

[0165] It should be noted that the embodiments and advantages of the doped portion 1240 can be combined with the embodiments and advantages of the first passivation contact portion 1220a and the first passivation contact portion 1220b illustrated in some of the aforementioned embodiments, and will not be further described here. For example, all doped portions 1240 can be arranged in a rectangular array. For another example, the doped portion 1240 can be configured as a strip structure like the first passivation contact portion 1220a. This is not a specific limitation.

[0166] According to some embodiments of this application, please refer to Figure 16 , Figure 16 Schematic diagram of a top view of the structure of the substrate 121 and the doping layer 124 b in some other embodiments of the present application. The doping layer 124 b is provided with a plurality of third through holes k3 penetrating the doping layer 124 b along the first direction F1.

[0167] The third through hole k3 penetrates the doping layer 124 b . That is, the third through hole k3 may expose a portion of one side of the second surface m2 of the substrate 121 opposite to the third through hole k3 .

[0168] For example, the cross section of the third through hole k3 perpendicular to the first direction F1 may be rectangular, circular, triangular or other shapes, which are not specifically limited here. Figure 16 For example, the cross section of the second through hole k2 perpendicular to the first direction F1 is a rectangular shape. The arrangement of the second through hole k2 can be understood and implemented with reference to the arrangement of the second passivation contact portion 1230 illustrated in some of the aforementioned embodiments, and is not specifically limited here. Figure 16 In the illustrated case, the plurality of second through holes k2 are arranged in a rectangular array.

[0169] In this way, the optical absorption of the doped layer 124 b can be reduced by forming the through hole.

[0170] According to some embodiments of this application, please continue to refer to Figure 14 and Figure 15The portion of the side of the substrate 121 facing away from the top cell 110a that is exposed through the doped layer 124a is a third sub-surface m22. The doped layer 124a has a third target surface t3 that is not in contact with the side of the substrate 121 facing away from the top cell 110a and is located within the tandem solar cell 100e. The tandem solar cell 100e also includes a fourth passivation layer 170, which is disposed on the third sub-surface m22 and the third target surface t3.

[0171] It can be understood that when the second surface m2 of the substrate 121 is diffused to form a doping diffusion layer to obtain the doping layer 124a, the side surface of the doping layer 124a that is away from the top battery unit 110a is the second surface m2. At this time, the third target surface t3 can be regarded as part of the second surface m2. The third sub-surface m22 is the surface of the substrate 121 exposed after removing or removing part of the doping layer 124a. The surface of the doping layer 124a includes a top surface that is set away from the top battery unit 110a and a side surface connected to the top surface. According to the structure of the doping layer 124a, the side surface of the doping layer 124a can be entirely located in the stacked solar cell 100e, or a part can be located in the stacked solar cell 100e, and the other part can not be located in the stacked solar cell 100e. For example, Figure 14 and Figure 15 For example, the case where the side surface of the doping layer 124a is entirely located within the stacked solar cell 100e is illustrated. When a portion of the side surface of the doping layer 124a is not located within the stacked solar cell 100e, the side surface of this portion can be flush with the side surface of the stacked solar cell 100e. That is, the third target surface t3 includes the aforementioned top surface of the doping layer 124a and the side surface of the doping layer 124a located within the stacked solar cell. When the doping layer 124a is formed on the second surface m2 of the substrate 121, the third sub-surface m22 and the third target surface t3 can be understood with reference to the aforementioned "first sub-surface m11 and first target surface t1" and "second sub-surface m21 and second target surface t2", and will not be described in detail here.

[0172] During the formation of the doped layer 124a, as described in the process of forming the first passivation contact layer, the use of a laser etching process carries the risk of thermal damage, mechanical stress damage, plasma damage, and the like. The use of a mask process carries the risk of etching damage, thermal stress damage, and the like, thereby risking damage to the doped layer 124a. Similarly, by providing a fourth passivation layer 170, the hydrogen content or charge density in the fourth passivation layer 170 can be controlled, thereby simultaneously passivating both damaged and undamaged portions of the surface of the doped layer 124a.

[0173] In this way, by setting the first passivation layer 140, not only can the defects be controlled more evenly and the boundary stress at the junction of damaged and undamaged areas be improved, thereby improving the consistency and reliability of the doping layer, but the potential energy barrier between film layers can also be reduced, which is beneficial to the conduction and collection of minority carriers by the battery, thereby improving the open circuit voltage and fill factor of the battery.

[0174] According to some embodiments of this application, please continue to refer to Figure 14 and Figure 15 The material of the fourth passivation layer 170 includes metal oxide, non-metal nitride or non-metal oxynitride.

[0175] For example, the metal oxide may be made of aluminum oxide, yttrium oxide, ytterbium oxide, silicon oxide, or the like. The non-metallic nitride may be made of silicon nitride, aluminum nitride, or the like. The non-metallic oxynitride may be made of silicon oxynitride, aluminum oxynitride, or the like. These are not specifically limited herein.

[0176] When the material of the fourth passivation layer 170 includes a metal oxide, the metal oxide can provide a high-density negative charge, thereby achieving a field passivation effect. When the material of the fourth passivation layer 170 includes a non-metallic nitride or a non-metallic oxynitride, the non-metallic nitride or non-metallic oxynitride can provide hydrogen atoms, which can diffuse to the surface of the fourth passivation contact layer to passivate dangling bonds, thereby achieving chemical passivation.

[0177] According to some embodiments of this application, please continue to refer to Figure 14 and Figure 15 The material of the fourth passivation layer 170 includes metal oxide, and the thickness of the fourth passivation layer 170 is 1nm to 50nm; or, the material of the fourth passivation layer 170 includes non-metal nitride or non-metal nitride oxide, and the thickness of the fourth passivation layer 170 is 50nm to 100nm.

[0178] The connotation and understanding of the thickness of the fourth passivation layer 170 can be understood by referring to the thickness of the first passivation layer 140 illustrated in some of the aforementioned embodiments, and will not be repeated here. Figure 15 For example, the thickness of the portion of the fourth passivation layer 170 located on the substrate 121 is the dimension of the portion along the first direction F1 (ie, the fourth dimension h4).

[0179] For example, when the material of the fourth passivation layer 170 includes a metal oxide, the thickness of the fourth passivation layer 170 can be 1 nm, 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 45 nm, or 50 nm. Of course, it can also be any other value within the range of 1 nm to 50 nm, and is not specifically limited here. When the material of the fourth passivation layer 170 includes a non-metallic nitride or a non-metallic oxynitride, the thickness of the fourth passivation layer 170 can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 77 nm, 80 nm, 90 nm, or 100 nm. Of course, it can also be any other value within the range of 50 nm to 100 nm, and is not specifically limited here.

[0180] In this way, by controlling the thickness of the fourth passivation layer 170 , the fourth passivation layer 170 can have a certain passivation effect and a certain carrier transmission capability.

[0181] According to some embodiments of this application, please continue to refer to Figure 1 、 Figure 7 、 Figure 9 、 Figure 11 and Figure 14 The top cell 110a includes a first charge transport layer 111, a light absorbing layer 112, a second charge transport layer 113 and a transparent electrode layer 114a stacked away from the bottom cell.

[0182] The first charge transport layer 111 and the second charge transport layer 113 can transport carriers. Sunlight can pass through the transparent electrode layer 114a, thereby facilitating the irradiation of the light absorbing layer 112 by sunlight, thereby generating a photocurrent in the stacked solar cell. Specifically, the light absorbing layer 112 can generate electron-hole pairs under the irradiation of sunlight. Both electrons and holes can be called carriers. The recombination layer can be used to modify the side surface of the top battery unit 110a facing the bottom battery unit. The electrons and holes of the top battery unit 110a can be recombined in the recombination layer to make the current of the bottom battery unit and the current of the top battery unit 110a consistent as much as possible.

[0183] For example, the first charge transport layer 111 and the second charge transport layer 113 can transport carriers and can be manufactured by one of the following processes: PVD (Physical Vapor Deposition) process, RPD (Rapid Plasma Deposition) process, thermal evaporation process, close space sublimation process, vapor transport deposition process, and spraying process. The material of the first charge transport layer 111 and the material of the second charge transport layer 113 can be PTAA, NiO x, V2O5, MoOx, PEDOT:PSS, WO x , CuSCN, Cu2O, CuI, and Spiro-TTB. Specifically, depending on the materials of the first charge transport layer 111 and the second charge transport layer 113, each of the above film layers can transport electrons or holes. For example, the first charge transport layer 111 is a hole transport layer, and the second charge transport layer 113 is an electron transport layer.

[0184] Exemplarily, the dimension of the first charge transport layer 111 along the first direction F1, that is, the thickness of the first charge transport layer 111, is 15 nm to 35 nm. For example, the thickness of the first charge transport layer 111 can be 15 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 33 nm, or 35 nm. Of course, it can also be any other value within the range of 15 nm to 35 nm, and is not specifically limited here.

[0185] Exemplarily, the dimension of the second charge transport layer 113 along the first direction F1, that is, the thickness of the second charge transport layer 113, is 10 nm to 30 nm. For example, the thickness of the second charge transport layer 113 can be 10 nm, 15 nm, 20 nm, 22 nm, 25 nm, 28 nm, or 30 nm. Of course, it can also be any other value within the range of 10 nm to 30 nm, and is not specifically limited here.

[0186] For example, the light absorbing layer 112 may be a perovskite layer. The chemical formula of the perovskite in the light absorbing layer 112 is ABX3. Wherein, A includes organic cations, inorganic cations or organic-inorganic mixed cations, B includes organic cations, inorganic cations or organic-inorganic mixed cations, and X includes organic anions, inorganic anions or organic-inorganic mixed anions. A may include FA + 、MA + 、Cs + or Rb + Any one or a combination of at least two of the following, B may include Pb 2+ 、Sn 2+ or Sr 2+ Any one or a combination of at least two of, X may include Br - , I - or CI - According to actual needs, a perovskite material with corresponding ions can be selected to prepare the perovskite layer (ie, the light absorbing layer 112), and no specific limitation is made here.

[0187] Exemplarily, the dimension of the light absorbing layer 112 along the first direction F1, i.e., the thickness of the light absorbing layer 112, is 500 nm to 1300 nm. For example, the thickness of the light absorbing layer 112 can be 500 nm, 600 nm, 650 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, or 1300 nm. Of course, the thickness can also be any other value within the range of 500 nm to 1300 nm, and is not specifically limited here.

[0188] Exemplarily, the material of the transparent electrode layer 114a includes a transparent metal oxide. Specifically, the material of the transparent electrode layer 114a may include at least one of ITO, IZO, AZO, IWO, SnO2, ZnO, strontium indium oxide, and IXO. The transparent electrode layer 114a may be manufactured using a PVD process or an RPD process.

[0189] Exemplarily, the thickness of the transparent electrode layer 114a may be 30 nm to 100 nm. For example, the thickness of the transparent electrode layer 114a may be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 75 nm, 80 nm, 90 nm, 95 nm, or 100 nm. Of course, the thickness may be any other value within the range of 30 nm to 100 nm, and is not specifically limited herein.

[0190] In this way, the required structure of the top battery unit 110 a can be obtained according to the above structure.

[0191] According to some embodiments of this application, please refer to Figure 17 , Figure 17 This is a schematic cross-sectional view of a tandem solar cell 100f in yet other embodiments of the present application. The top cell 110b includes a first charge transport layer 111, a light absorbing layer 112, a second charge transport layer 113, and a transparent electrode layer 114b, stacked along a surface facing away from the bottom cell 120b. The transparent electrode layer 114b includes a first sublayer 1141 and a second sublayer 1142. The first sublayer 1141 is disposed on a surface of the second charge transport layer 113 facing away from the light absorbing layer 112, and the second sublayer 1142 is disposed on a surface of the first sublayer 1141 facing away from the second charge transport layer 113. The orthographic projection and the overlapping projection of the first sublayer 1141 on a reference plane E overlap. The orthographic projection of the second sublayer 1142 on the reference plane E lies within the overlapping projection, and the area of ​​the orthographic projection of the second sublayer 1142 on the reference plane E is smaller than the area of ​​the overlapping projection.

[0192] Thus, the transparent electrode layer 114b includes the first sublayer 1141, so that the transparent electrode layer 114b retains a certain film thickness, which is conducive to lateral transmission. The transparent electrode layer 114b includes the second sublayer 1142, which can reduce parasitic absorption of light while facilitating charge transmission.

[0193] It should be noted that the arrangement and construction of the second sub-layer 1142 can be understood with reference to the first passivation contact portion 1220a and the first passivation contact portion 1220b illustrated in some of the aforementioned embodiments, and no further details are given here. For example, the second sub-layer 1142 may include a plurality of spaced-apart sub-structures, and all sub-structures may be arranged in a rectangular array or in a strip shape, without specific limitation here. For another example, a related through-hole structure may be provided on the second sub-layer 1142, and the arrangement and implementation of the related through-hole structure may refer to the first through-hole k1 illustrated in some of the aforementioned embodiments, without specific limitation here. Figure 17 The thickness of each layer in the top battery unit 110b can be referred to the aforementioned Figure 1 、 Figure 7 、 Figure 9 、 Figure 11 and Figure 14 The thickness of each layer in the top battery unit 110a is shown in FIG. 1 and will not be described in detail here. Figure 17 The sum of the thicknesses of the second sublayer 1142 and the portion of the first sublayer 1141 corresponding to the second sublayer 1142 in the transparent electrode layer 114b illustrated in FIG. 1 may be understood with reference to the thickness of the transparent electrode layer 114a illustrated above.

[0194] According to some embodiments of this application, please continue to refer to Figure 17 The top battery unit 110b further includes a protective layer 115 disposed on a surface of the transparent electrode layer 114b facing away from the bottom battery unit 120b.

[0195] Exemplarily, the thickness of the protective layer 115 is 50 nm to 200 nm. For example, the thickness of the transparent electrode layer 114 b can be 50 nm, 60 nm, 70 nm, 75 nm, 80 nm, 90 nm, 100 nm, 150 nm, 180 nm, or 200 nm. Of course, any other value within the range of 50 nm to 200 nm is also possible, and is not specifically limited here.

[0196] In this way, the transparent electrode layer 114 b can be protected by providing the protective layer 115 , thereby improving the reliability of the transparent electrode layer 114 b .

[0197] Of course, in Figure 1 、 Figure 7 、 Figure 9 、 Figure 11 and Figure 14The top cell 110 a shown also includes a protection layer 115 disposed on a surface of the transparent electrode layer 114 a facing away from the bottom cell.

[0198] According to some embodiments of this application, please continue to refer to Figure 17 The stacked solar cell 100f further includes a first electrode 180 , the orthographic projection of the first electrode 180 on the reference plane E is located within the orthographic projection range of the second sublayer 1142 on the reference plane E, and the first electrode 180 forms an ohmic contact with at least the second sublayer 1142 .

[0199] For example, the material of the first electrode 180 includes at least one of Ag, Cu, Ni, or Al. The first electrode 180 can be manufactured by screen printing, electroplating, laser transfer, or thermal evaporation.

[0200] Since the transparent electrode layer 114b is used to conduct electrons, and the size of the portion of the transparent electrode layer 114b corresponding to the first electrode 180 in the first direction F1 is relatively larger than that of other portions of the transparent electrode layer 114b, it is beneficial to reduce parasitic absorption while facilitating the connection between the first electrode 180 and the transparent electrode layer 114b.

[0201] According to some embodiments of this application, please continue to refer to Figure 17 The stacked solar cell 100f further includes a second electrode 190 disposed on a side of the substrate 121 away from the top cell unit 110b. The second electrode 190 forms an ohmic contact with the second passivation contact layer 123b.

[0202] For example, the material of the second electrode 190 includes at least one of Ag, Cu, Ni, or Al. The first electrode 180 can be manufactured by screen printing, electroplating, laser transfer, or thermal evaporation.

[0203] Of course, in Figure 1 、 Figure 7 、 Figure 9 、 Figure 11 and Figure 14 The illustrated tandem solar cell also includes a second electrode 190 disposed on a side of the substrate 121 facing away from the top cell unit 110a. Figure 1 、 Figure 7 and Figure 9 In the illustrated embodiment, the second electrode 190 forms an ohmic contact with the second doped conductive layer 1232a. Figure 11 In the illustrated embodiment, the second electrode 190 forms an ohmic contact with the second doped conductive layer 1232b. Figure 14 In the illustrated embodiment, the second electrode 190 forms an ohmic contact with the doping layer 124 a .

[0204] It should be noted that the above embodiments illustrate the situation in which the first passivation contact layer, the second passivation contact layer, the doping layer, the composite layer and the transparent electrode layer are improved to reduce parasitic absorption. The improvement refers to the situation in which, for a layer structure that covers the entire layer, the layer structure partially covers the corresponding surface or the layer structure is partially removed. For example, the first passivation contact layer (combined with reference to Figure 1 、 Figure 7 、 Figure 9 、 Figure 11 、 Figure 14 and Figure 17 ), the second passivation contact layer (combined with reference Figure 11 and Figure 17 ) and doping layers (combined with reference Figure 14 ) is a case of partial coverage. At this time, since these layer structures have good lateral transmission performance, they have little effect on the transmission and collection of charges. Thus, they can reduce parasitic absorption while maintaining certain lateral transmission performance, thereby improving the short circuit. For example, the composite layer (combined with reference Figure 7 、 Figure 9 、 Figure 11 、 Figure 14 and Figure 17 ) and the transparent electrode layer (combined with reference Figure 17 ) refers to the removal of a portion of the structure, which helps reduce parasitic absorption while maintaining certain lateral transmission performance. It is understood that in a tandem solar cell involving the first passivation contact layer, second passivation contact layer, doped layer, composite layer, and transparent electrode layer, improvements can be made to at least one of the layers involved. This process can be accomplished through laser etching or masking, without specific limitations.

[0205] For example, when the stacked solar cell includes a first passivation contact layer, a second passivation contact layer, a composite layer and a transparent electrode layer, at least one of the first passivation contact layer, the second passivation contact layer, the composite layer and the transparent electrode layer may be improved to reduce parasitic absorption. In other words, it may be that only the first passivation contact layer is improved, or the first passivation contact layer and the second passivation contact layer are improved, or the first passivation contact layer, the second passivation contact layer and the composite layer are improved, or the first passivation contact layer, the second passivation contact layer, the composite layer and the transparent electrode layer are improved, and so on, and there is no specific limitation here. Figure 1 As an example, the first passivation contact layer 122a in the stacked solar cell 100a is improved. Figure 7 and Figure 9As an example, the first passivation contact layer 122a and the composite layer 130b in the stacked solar cell 100b and the stacked solar cell 100c are shown as improved. Figure 11 As an example, the first passivation contact layer 122a, the composite layer 130b and the second passivation contact layer 123b in the stacked solar cell 100d are shown as improved. Figure 17 As an example, the situation in which the first passivation contact layer 122a, the second passivation contact layer 123b, the composite layer 130b and the transparent electrode layer 114b in the stacked solar cell 100f are improved is illustrated.

[0206] For example, when the stacked solar cell includes a first passivation contact layer, a doping layer, a composite layer and a transparent electrode layer, at least one of the first passivation contact layer, the doping layer, the composite layer and the transparent electrode layer may be improved to reduce parasitic absorption. In other words, the improvement may be made only to the first passivation contact layer, or to the first passivation contact layer and the doping layer, or to the first passivation contact layer, the doping layer and the composite layer, or to the first passivation contact layer, the doping layer, the composite layer and the transparent electrode layer, etc., and no specific limitation is made here. Figure 14 As an example, the situation in which the first passivation contact layer 122a, the composite layer 130b and the doping layer 124a in the stacked solar cell 100e are improved is illustrated.

[0207] It should be noted that when improvements are made to the first passivation contact layer, the second passivation contact layer, the doped layer, and the composite layer, a passivation layer may or may not be provided on the improved layer structure. In some of the above embodiments, the first passivation layer 140, the second passivation layer 150, the third passivation layer 160b, and the fourth passivation layer 170 are provided.

[0208] Exemplary, with reference to Figure 18 , Figure 18 This is a schematic cross-sectional view of a tandem solar cell 100g in yet other embodiments of the present application. Improvements have been made to the first passivation contact layer 122a, the second passivation contact layer 123b, the composite layer 130b, and the transparent electrode layer 114b. Specifically, a first passivation layer 140 is disposed on the first passivation contact layer 122a, a second passivation layer 150 is disposed on the composite layer 130b, and a third passivation layer 160b is disposed on the second passivation contact layer 123b.

[0209] Exemplary. Combined with reference Figure 19 , Figure 19This is a schematic cross-sectional view of a tandem solar cell 100i in yet other embodiments of the present application. Improvements have been made to the first passivation contact layer 122a, doping layer 124a, composite layer 130b, and transparent electrode layer 114b. Specifically, a first passivation layer 140 is disposed on the first passivation contact layer 122a, a second passivation layer 150 is disposed on the composite layer 130b, and a fourth passivation layer 170 is disposed on the doping layer 124a.

[0210] Therefore, in the situations illustrated in some of the above embodiments, the improvements to the structures of the various layers and the addition of the passivation layer may be combined, and no specific limitation is imposed herein.

[0211] Because each film layer in the tandem solar cell in the related art is a full-surface film layer, although it is beneficial for charge extraction and transmission, the excessive film layers will inevitably lead to an increase in unusable light and increased parasitic absorption, resulting in a large light loss in the tandem solar cell across the entire spectrum, which has a significant impact on the short-circuit current and makes it difficult to improve the efficiency of the tandem solar cell. In addition, because most of the film layers in the tandem solar cell are irreplaceable, it is difficult to improve the efficiency of the tandem solar cell by reducing the number of film layers.

[0212] In conjunction with the situations illustrated in some of the above embodiments, the embodiments of the present application improve the relevant layer structures involved in the stacked solar cell, thereby reducing parasitic absorption, increasing short-circuit current, and thus improving efficiency. In this process, not only can the optical loss of the entire stacked solar cell be reduced, the light response of different wavelengths be improved, and the short-circuit current of the battery be increased, but the physical contact area and electrical connection efficiency of the interface can also be increased, the resistance between the interfaces can be reduced, and the conduction and collection of minority carriers by the battery can be improved, thereby improving the fill factor of the battery. At the same time, the relevant passivation layer is used to reduce the composite defects at the interface, so that a certain open circuit voltage and fill factor can be achieved.

[0213] In particular, in the formation of Figure 18 and Figure 19The illustrated structure forms an alternating arrangement of an improved layer structure and a passivation layer, essentially forming a stacked structure comprising a first passivation contact layer 122a, a first passivation layer 140, a recombination layer 130b, and a second passivation layer 150. Furthermore, the side of the substrate 121 facing away from the top cell 110b also has an improved layer structure and a passivation layer. This alternating structure, with most layers improved and complemented by a passivation layer, not only further reduces optical losses and improves short-circuit current, but also reduces defects and recombination centers through the passivation layer, and mitigates the potential energy barrier of the film layers, enabling rapid minority carrier transport and improving the open-circuit voltage and fill factor of the stacked solar cell. Therefore, in this scenario, the coordination and synergy between the film layers can increase the short-circuit current while maintaining a certain open-circuit voltage and fill factor, thereby further improving the efficiency of the cell.

[0214] The following is an illustrative description of the stacked solar cell provided in the embodiments of the present application in combination with the contents illustrated in some of the above embodiments, but the invention is not limited thereto.

[0215] Exemplary, with reference to Figure 18 The manufacturing method of the stacked solar cell 100g includes the following steps:

[0216] Step S1, providing a substrate 121, wherein the substrate 121 is an N-type single crystal silicon wafer;

[0217] Step S2: forming an initial second tunneling layer on the second surface m2 of the substrate 121 by using a low pressure chemical vapor deposition method;

[0218] Step S3: depositing an amorphous silicon layer on the surface of the initial second tunneling layer facing away from the substrate 121 in a high-temperature diffusion furnace, and then performing boron diffusion and oxidation annealing to form a P-type polysilicon layer, which serves as the initial second doped conductive layer;

[0219] Step S4: Processing the initial second tunneling layer and the initial second doped conductive layer by laser etching to form a second tunneling layer 1231b and a second doped conductive layer 1232b, wherein the second tunneling layer 1231b and the second doped conductive layer 1232b constitute a second passivation contact layer 123b;

[0220] Step S5: performing a passivation treatment on the second passivation contact layer 123b in a high-temperature diffusion furnace to form a third passivation layer 160b;

[0221] Step S6: Printing an electrode at a position corresponding to the second passivation contact layer 123 b by screen printing, and then performing high-temperature sintering and annealing at a temperature of 600° C. to 900° C. to form a second electrode 190 in ohmic contact with the second doped conductive layer 1232 b ;

[0222] Step S7: forming an initial first tunneling layer on the first surface m1 of the substrate 121 by using a low pressure chemical vapor deposition method;

[0223] Step S8: depositing an amorphous silicon layer on the surface of the initial first tunneling layer facing away from the substrate 121 in a high-temperature diffusion furnace, and then performing phosphorus diffusion and oxidation annealing to form an N-type polysilicon layer, which serves as the initial first doped conductive layer;

[0224] Step S9: Processing the initial first tunneling layer and the initial first doped conductive layer by a laser etching process to form a first tunneling layer 1221a and a first doped conductive layer 1222a, wherein the first tunneling layer 1221a and the first doped conductive layer 1222a constitute a first passivation contact layer 122a;

[0225] Step S10: performing a passivation treatment on the first passivation contact layer 122a in a high-temperature diffusion furnace to form a first passivation layer 140;

[0226] Step S11, sputtering ITO on the surface by PVD process at 300° C. to 500° C. to form an initial composite layer;

[0227] Step S12: thinning the portion of the initial composite layer corresponding to the substrate 121 not covered by the first passivation contact layer 122 a by a laser etching process to form a composite layer 130 b , and forming a second passivation layer 150 on a surface of the composite layer 130 b facing away from the substrate 121 ;

[0228] Step S13: Weigh a certain amount of hole transport material and completely dissolve it in 2 mL of a mixed solution of anhydrous ethanol and DMSO. Take an appropriate amount of the solution and drop it onto the surface of the second passivation layer 150 facing away from the composite layer 130 b. Spin-coat at 3000 rpm for 25 to 30 seconds, and then anneal at 90° C. to 110° C. for 10 minutes to form the first charge transport layer 111.

[0229] Step S14: forming a perovskite layer on a surface of the first charge transport layer 111 facing away from the second passivation layer 150 , wherein the perovskite layer serves as the light absorption layer 112 ;

[0230] Step S15: forming a second charge transport layer 113 made of C60 by evaporation on a side of the light absorbing layer 112 away from the first charge transport layer 111;

[0231] Step S16: forming an initial transparent electrode layer made of IZO on the surface of the second charge transport layer 113 facing away from the light absorption layer 112 by a magnetron sputtering process;

[0232] Step S17: Processing the initial transparent electrode layer by laser etching to form a transparent electrode layer 114b including a first sublayer 1141 and a second sublayer 1142; wherein the second sublayer 1142 is provided corresponding to the first passivation contact layer 122a;

[0233] Step S18 : forming a first electrode 180 made of silver by evaporation at a position corresponding to the second sub-layer 1142 of the transparent electrode layer 114 b .

[0234] In the manufacturing process shown above, a protective layer 115 made of MgF2 can be formed by evaporation on the transparent electrode layer 114b and the first electrode 180. Figure 19 The illustrated stacked solar cell 100i differs from the manufacturing process illustrated above in that the second surface m2 of the substrate 121 is diffused in a diffusion furnace containing a P-type dopant element to form an initial doped diffusion layer, and then the doped diffusion layer is formed by a laser etching process, and then the fourth passivation layer 170 is formed. When forming the layer structure that needs to be improved as mentioned above, a mask process can also be used for production, and no specific limitation is made here. It should be noted that the steps in the manufacturing method illustrated above do not necessarily have to be produced in the order of the steps illustrated above. For example, if it is feasible and easy to operate, the first passivation contact layer can also be produced first, and then the second passivation contact layer can be produced. No specific limitation is made here.

[0235] The following is an exemplary description of the stacked solar cell in the embodiments of the present application, with reference to the structures of the stacked solar cell illustrated in some of the above embodiments and related comparative examples.

[0236] In Example 1, the Figure 1The structure of the stacked solar cell 100a is shown. The substrate 121 is an N-type single-crystal silicon substrate with a thickness of 180μm; the first tunneling layer 1221a is made of silicon oxide with a thickness of 1.5nm; the first doped conductive layer 1222a is a phosphorus-doped polysilicon layer with a thickness of 200nm; the first passivation layer 140 is made of aluminum oxide with a thickness of 2nm; the second tunneling layer 1231a is made of silicon oxide with a thickness of 2nm; the second doped conductive layer 1232a is a boron-doped polysilicon layer with a thickness of 250nm; the third passivation layer 160a is made of silicon nitride with a thickness of 100nm; the composite layer 130a is made of ITO with a thickness of 30nm; the first charge transport layer 111 is made of doped NiO with a thickness of The thickness is 10nm; the light absorption layer 112 is made of perovskite and has a thickness of 900nm; the second charge transport layer 113 is made of C60 and has a thickness of 20nm; the transparent electrode layer 114a is made of IZO and has a thickness of 80nm; the protective layer 115 is made of magnesium fluoride and has a thickness of 90nm; the first electrode 180 is made of silver, and there are 2 main grid lines and 6 auxiliary grid lines in the first electrode 180. The width of the main grid line is 150μm, and the width of the auxiliary grid line is 80μm; the second electrode 190 is made of silver paste, and there are 3 main grid lines and 10 auxiliary grid lines in the second electrode 190. The width of the main grid line is 200μm, and the width of the auxiliary grid line is 100μm.

[0237] In Example 2, different from Example 1, the Figure 4 The first passivation contact layer 122 b is shown in the figure, and the area of ​​the first passivation contact layer 122 b on the first surface m1 of the substrate 121 accounts for 45%.

[0238] In Example 3, different from Example 1, the Figure 5 In the illustrated first passivation contact layer 122 c , the area of ​​the first through hole k1 on the first surface m1 of the substrate 121 accounts for 55%.

[0239] In Example 4, different from Example 1, the Figure 6 The first passivation contact layer 122d is shown in the diagram, and the area of ​​the first passivation contact layer 122d on the first surface m1 of the substrate 121 accounts for 30%.

[0240] In Example 5, different from Example 1, the Figure 7 In the structure of the stacked solar cell 100 b shown in FIG, the thickness of the first portion 131 of the composite layer 130 b is 30 nm, and the thickness of the portion of the second portion 132 that is not in contact with the first passivation contact layer 122 a is 5 nm.

[0241] In Example 6, different from Example 5, the Figure 9The structure of the stacked solar cell 100 c is shown schematically, and a second passivation layer 150 is provided. The material of the second passivation layer 150 is 2PACz, and the thickness is 3 nm.

[0242] In Example 7, different from Example 5, the Figure 11 In the structure of the stacked solar cell 100d shown, the second tunneling layer 1231b is made of silicon oxide with a thickness of 2 nm; the second doped conductive layer 1232b is a boron-doped polysilicon layer with a thickness of 250 nm; and the third passivation layer 160b is made of silicon nitride with a thickness of 100 nm.

[0243] In Example 8, different from Example 6, the second passivation contact layer in Example 7 is adopted, that is, the material of the second tunneling layer 1231b is silicon oxide with a thickness of 2nm; the second doped conductive layer 1232b is a boron-doped polysilicon layer with a thickness of 250nm; the material of the third passivation layer 160b is silicon nitride with a thickness of 100nm.

[0244] In Example 9, different from Example 1, the Figure 14 The structure of the stacked solar cell 100e shown does not use a second passivation contact layer, but uses a doped layer 124a; the doped layer 124a is a boron diffusion layer with a thickness of 500nm; the fourth passivation layer is made of silicon nitride with a thickness of 90nm; the first portion 131 of the composite layer 130b has a thickness of 30nm, and the portion of the second portion 132 that is not in contact with the first passivation contact layer 122a has a thickness of 5nm.

[0245] In Example 10, different from Example 9, the Figure 19 The structure of the stacked solar cell 100i is shown schematically, and a second passivation layer 150 is provided. The material of the second passivation layer 150 is 2PACz, and the thickness is 3 nm.

[0246] In Example 11, different from Example 7, the Figure 17 In the structure of the stacked solar cell 100 f shown in FIG, the transparent electrode layer 114 b is made of IZO, the thickness of the first sublayer 1141 is 20 nm, and the thickness of the second sublayer 1142 is 80 nm.

[0247] In Example 12, different from Example 11, the Figure 18 The structure of the stacked solar cell 100g is shown schematically, and a second passivation layer 150 is provided. The material of the second passivation layer 150 is 2PACz, and the thickness is 3 nm.

[0248] In Comparative Example 1, different from Example 1, a first tunneling layer and a first doped conductive layer are provided as a whole layer; the first tunneling layer is made of silicon oxide with a thickness of 1.5 nm; and the first doped conductive layer is a phosphorus-doped polysilicon layer with a thickness of 200 nm.

[0249] In Comparative Example 2, different from Example 9, a doped layer is used as a whole layer, and the first tunneling layer, the first doped conductive layer and the composite layer are arranged as a whole layer; the doped layer is a boron diffusion layer with a thickness of 500nm; the material of the first tunneling layer is silicon oxide with a thickness of 1.5nm; the first doped conductive layer is a phosphorus-doped polysilicon layer with a thickness of 200nm; the material of the composite layer is ITO with a thickness of 30nm.

[0250] In Comparative Example 3, unlike Example 1, no first passivation layer is provided.

[0251] The cells prepared in Examples 1 to 12 and Comparative Examples 1 to 3 were tested using a solar simulator under AM1.5G simulated sunlight at 25 degrees Celsius. The test results are shown in Table 1. The effective area of ​​the stacked solar cell is 1 cm 2 .

[0252] Table 1

[0253]

[0254] It can be seen from Table 1 that, compared with Comparative Examples 1 to 3, the conversion efficiency of Examples 1 to 12 is higher overall.

[0255] Among them, compared with Comparative Examples 1 to 3, in Example 1, the first doped conductive layer is patterned in strips, which not only reduces the parasitic absorption of the first doped conductive layer, allowing the crystalline silicon layer to obtain more light sources and increase the short-circuit current of the battery, but also adds an aluminum oxide passivation layer to reduce defects in the first doped conductive layer and the patterned area, reduce recombination centers, and prevent the open circuit voltage and fill factor from decreasing, thereby improving the efficiency of the stacked battery as a whole.

[0256] In Example 2, the graphic shape of the first doped conductive layer is transformed from a strip shape into multiple independent parts, so that the storage area of ​​the first doped conductive layer is smaller, more incident light is effectively utilized, and the short-circuit current is further improved. However, the first doped conductive layer is in an island shape and is less connected to each other and more damaged. After passivation, there is a slight decrease in the open circuit voltage and fill factor. Although the final efficiency improvement of the stacked battery is not as good as that of Example 1, it is still higher than that of Comparative Example 1, and still has certain advantages.

[0257] In Example 3, part of the first doped conductive layer is dug out to form a hollow structure, and most of the first doped conductive layer structure can be retained. Although the short-circuit current is less increased, the first doped conductive layer is less damaged as a whole. After passivation, normal open-circuit voltage and fill factor can be obtained, and the stacking efficiency can still be improved.

[0258] In Example 4, the first doped conductive layer is roughly arranged in a mesh shape, which increases the short-circuit current while ensuring that the remaining first doped conductive layers are connected to each other, so that carriers can be transmitted faster, the open-circuit voltage and fill factor decrease less after passivation, the combined current is greatly improved, and the overall stacking efficiency is greatly improved.

[0259] In Example 5, the composite layer is further patterned on the basis of Example 1. Due to the damage to the composite layer, the charge transfer is greatly affected, so the open circuit voltage and fill factor decrease, and the advantage of improving battery efficiency is relatively small, but the battery efficiency is still improved overall.

[0260] In Example 6, based on Example 5, the composite layer is passivated to reduce defects and recombination centers in the composite layer, reduce the probability of carrier capture, and improve the energy level matching between the first doped conductive layer and the first charge transfer layer, which can greatly improve the open circuit voltage and fill factor, and further improve the stacking efficiency.

[0261] In Example 7, the first doped conductive layer is patterned to reduce the parasitic absorption of long-wavelength light by the bottom battery unit, so that more long-wavelength light is absorbed by the crystalline silicon layer, generating more photogenerated carriers, further improving the short-circuit current of the stacked battery. In addition, the patterning of the first doped conductive layer will cooperate with the passivation treatment, and the passivation effect of the etched part is better than that of the first doped conductive layer part. Therefore, the open-circuit voltage will be improved. Combined with the improvement of the short-circuit current, the battery efficiency can be further improved.

[0262] In Example 8, the composite layer is passivated based on Example 7, the open circuit voltage and filling are improved, and the battery efficiency is improved.

[0263] In Example 9, the second doped conductive layer is replaced by a boron diffusion layer, and the passivation effect of the second passivation contact layer is lost, and the open circuit voltage will decrease. However, since there is no obvious parasitic absorption produced by the second doped conductive layer, the short-circuit current of the battery is increased again. Due to the damage to the composite layer, the fill factor is low and the battery efficiency changes little.

[0264] In Example 10, the composite layer is passivated based on Example 9, the open circuit voltage and filling are improved, and the battery efficiency is improved.

[0265] In Example 11, the transparent electrode layer is patterned, which not only reduces the reflection of incident light, but also reduces the parasitic absorption of the transparent electrode layer itself, allowing more light to reach other functional layers, generating more photogenerated carriers, thereby increasing the short-circuit current of the battery and further improving the overall efficiency.

[0266] In Example 12, the composite layer is passivated based on Example 11, defects are reduced, charge transfer is smoother, open circuit voltage and fill factor are improved, and battery efficiency is further improved.

[0267] In particular, in Examples 10 and 12, due to the synergistic effect of overall patterning, optical losses can be reduced and contact area can be increased, the light response to each band can be improved and the contact resistance can be reduced, the functional layer can generate more photogenerated carriers, and the short-circuit current can be greatly improved. The added passivation layer can reduce interface recombination defects and enhance the battery's conduction and collection of minority carriers, so that the open circuit voltage and fill factor can remain unchanged, and the resulting battery efficiency is greatly improved.

[0268] It can be seen from this that the stacked solar cell provided in the embodiment of the present application has more advantages.

[0269] It should be noted that the aforementioned patterning process refers to a process in which a portion of the corresponding layer is removed from the entire layer. The patterning process can be performed using a process such as the laser etching process illustrated in some of the aforementioned embodiments, which will not be described in detail here.

[0270] According to some embodiments of this application, please refer to Figure 20 , Figure 20 The following is a schematic diagram of the structure of a photovoltaic module 10 in some embodiments of the present application. The embodiments of the present application provide a photovoltaic module 10, comprising a cell string 11, an encapsulation layer 12, and a cover plate 13. The encapsulation layer 12 is used to cover the surface of the cell string 11. The cover plate 13 is used to cover the surface of the encapsulation layer 12 away from the cell string 11. The cell string 11 is formed by connecting a plurality of stacked solar cells as described in any of the above embodiments.

[0271] In some embodiments, the plurality of cell strings 11 may be electrically connected via conductive ribbons 14. The encapsulation layer 12 covers the front and back surfaces of the stacked solar cell.

[0272] In some embodiments, the encapsulation layer 12 may be an organic encapsulation film such as an ethylene vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer (POE) film, or a polyethylene terephthalate (PET) film.

[0273] In some embodiments, the cover plate 13 may be a glass cover plate, a plastic cover plate or other light-transmitting cover plate.

[0274] In some embodiments, the surface of the cover plate 13 facing the encapsulation layer 12 may be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0275] The photovoltaic module 10 also has the advantages of the above-mentioned stacked solar cell, which will not be described in detail here.

[0276] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0277] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A stacked solar cell, characterized in that: The battery comprises a top battery cell and a bottom battery cell stacked along a first direction, and a composite layer located between the top battery cell and the bottom battery cell; the orthographic projections of the top battery cell and the bottom battery cell on a reference plane have overlapping projections, and the reference plane is a plane perpendicular to the first direction; The bottom battery cell includes a substrate and a first passivation contact layer, the first passivation contact layer including a first tunneling layer and a first doped conductive layer stacked on a surface of the substrate facing the top battery cell; the orthographic projection of the first passivation contact layer on the reference plane is located within the overlapping projection range, and the area of ​​the orthographic projection of the first passivation contact layer on the reference plane is smaller than the area of ​​the overlapping projection; A portion of the substrate surface facing the top cell unit, which is exposed through the first passivation contact layer, is a first sub-surface; the first passivation contact layer has a first target surface that is not in contact with the substrate surface facing the top cell unit and is located within the tandem solar cell; The stacked solar cell further includes a first passivation layer, which is provided on the first sub-surface and the first target surface; the composite layer and the first passivation layer are in contact with each other on their facing surfaces.

2. The tandem solar cell according to claim 1, wherein The first passivation contact layer includes a plurality of first passivation contact portions arranged at intervals.

3. The tandem solar cell according to claim 2, wherein: At least some of the first passivation contact portions are spaced apart along the second direction, and the first passivation contact portions are longitudinally extended along the third direction; The second direction and the third direction intersect each other and are both perpendicular to the first direction.

4. The tandem solar cell according to claim 1, wherein The first passivation contact layer is provided with a plurality of first through holes penetrating the first passivation contact layer along the first direction.

5. The tandem solar cell according to claim 1, wherein: The first passivation contact layer includes a plurality of first sub-portions and a plurality of second sub-portions; The first sub-sections are extended along the fourth direction and spaced apart along the fifth direction; the second sub-sections are spaced apart along the fourth direction; each of the second sub-sections is connected to any one of all the first sub-sections; The fourth direction and the fifth direction intersect with each other and are both perpendicular to the first direction.

6. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The material of the first passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

7. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The material of the first passivation layer includes metal oxide, and the thickness of the first passivation layer is 1 nm to 50 nm; or The material of the first passivation layer includes non-metal nitride or non-metal oxynitride, and the thickness of the first passivation layer is 50 nm to 100 nm.

8. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The composite layer includes a first portion and a second portion; An orthographic projection of the first portion on the reference plane and an orthographic projection of the first passivation contact layer on the reference plane overlap with each other; A thickness of a portion of the second portion that is not in contact with the first passivation contact layer is smaller than a thickness of the first portion.

9. The tandem solar cell according to claim 8, characterized in that: The stacked solar cell further includes a second passivation layer, which is disposed on a surface of the composite layer that is away from the bottom battery unit.

10. The tandem solar cell according to claim 9, characterized in that: The second passivation layer is configured as a monomolecular layer.

11. The tandem solar cell according to claim 9, characterized in that: The thickness of the second passivation layer is 0.3 nm to 2 nm.

12. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The bottom battery cell further includes a second passivation contact layer, the second passivation contact layer including a second tunneling layer and a second doped conductive layer stacked on a surface of the substrate facing away from the top battery cell; The orthographic projection of the second passivation contact layer on the reference plane is located within the overlapping projection range, and the area of ​​the orthographic projection of the second passivation contact layer on the reference plane is smaller than the area of ​​the overlapping projection.

13. The tandem solar cell according to claim 12, characterized in that: The second passivation contact layer includes a plurality of second passivation contact portions arranged at intervals.

14. The tandem solar cell according to claim 12, characterized in that: The second passivation contact layer is provided with a plurality of second through holes penetrating the second passivation contact layer along the first direction.

15. The tandem solar cell according to claim 12, characterized in that: A portion of the substrate surface facing away from the top cell unit, which is exposed through the second passivation contact layer, is a second sub-surface; the second passivation contact layer has a second target surface that is not in contact with the substrate surface facing away from the top cell unit and is located within the tandem solar cell; The stacked solar cell further includes a third passivation layer, and the third passivation layer is disposed on the second sub-surface and the second target surface.

16. The tandem solar cell according to claim 15, characterized in that: The material of the third passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

17. The tandem solar cell according to claim 15, characterized in that: The material of the third passivation layer includes metal oxide, and the thickness of the third passivation layer is 1 nm to 50 nm; or The material of the third passivation layer includes non-metal nitride or non-metal oxynitride, and the thickness of the third passivation layer is 50 nm to 100 nm.

18. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The bottom battery cell further comprises a doping layer provided on a surface of the substrate facing away from the top battery cell; The orthographic projection of the doping layer on the reference plane is located within the overlapping projection range, and the area of ​​the orthographic projection of the doping layer on the reference plane is smaller than the area of ​​the overlapping projection.

19. The tandem solar cell according to claim 18, characterized in that: The doping layer includes a plurality of doping portions arranged at intervals.

20. The tandem solar cell according to claim 18, characterized in that The doping layer is provided with a plurality of third through holes penetrating the doping layer along the first direction.

21. The tandem solar cell according to claim 18, characterized in that A portion of the side of the substrate facing away from the top cell unit that is exposed through the doped layer is a third sub-surface; the doped layer has a third target surface that is not in contact with the side of the substrate facing away from the top cell unit and is located within the tandem solar cell; The stacked solar cell further includes a fourth passivation layer, and the fourth passivation layer is disposed on the third sub-surface and the third target surface.

22. The tandem solar cell according to claim 21, characterized in that: The material of the fourth passivation layer includes metal oxide, non-metal nitride or non-metal oxynitride.

23. The tandem solar cell according to claim 21, characterized in that The material of the fourth passivation layer includes metal oxide, and the thickness of the fourth passivation layer is 1 nm to 50 nm; or The material of the fourth passivation layer includes non-metal nitride or non-metal nitride oxide, and the thickness of the fourth passivation layer is 50 nm to 100 nm.

24. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The top battery unit includes a first charge transport layer, a light absorbing layer, a second charge transport layer and a transparent electrode layer stacked away from the bottom battery unit; The transparent electrode layer includes a first sublayer and a second sublayer, the first sublayer is provided on a surface of the second charge transport layer facing away from the light absorption layer, and the second sublayer is provided on a surface of the first sublayer facing away from the second charge transport layer; The orthographic projection of the first sub-layer on the reference plane and the overlapping projection overlap each other; The orthographic projection of the second sub-layer on the reference plane is located within the overlapping projection range, and the area of ​​the orthographic projection of the second sub-layer on the reference plane is smaller than the area of ​​the overlapping projection.

25. A photovoltaic module, characterized in that: include: Battery string; an encapsulation layer, used to cover the surface of the battery string; and a cover plate, the cover plate being used to cover a surface of the encapsulation layer away from the battery string; Wherein, the cell string is formed by connecting a plurality of stacked solar cells according to any one of claims 1 to 24.

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